“It is possible you might see someone being Mechalal Shabbos or eating at McDonalds. You are unlikely too see anyone doing averiahs specified in Vayaikra even if you suspect they are Oyver them “
There are massive differences
1)
These are of the 7 mitzvos bnei noach
2)There is no din of tinok shenishba for Noachide commandments
3)These are part of a societal or global Poretz Gidros Olam
(the first person in a shtetl to publibly be mechalel shabbos or have eaten treif would also have been a poretz geder with all that then would apply)